widget: resource search autocomplete

Use #13 to implement a combined "smart resource resolver" control which allows network participants to quickly find resource types & definitions they commonly use.

The autocomplete should match the entered text against text fields in EconomicResources, ResourceSpecifications and ResourceClassifications and surface matches grouped in the same order.

The idea is to show more specific types of things in a first phase. Higher-order components extending this one could be authored which add additional intelligence- eg. ordering frequently used matches with higher priority based on prior use.